This invention relates to fuel injection regulating or control valve and more particularly to such a valve with a rotating and axially movable valve member.
One type of known fuel injection system, such as described in U.S. Pat. No. 3,894,518, issued 15 July 1978 to Gavrun et al, includes a cam driven oscillating piston type metering pump. Such systems have high speed limitations because at high speeds the piston may lift off of the driving cam. Also, in multi-unit engines having multiple piston pumps all controlled by a common rack, the failure or seizure of one piston pump can prevent the other piston pumps from being adjusted to a minimum fuel condition. With no shut-off capability, the engine can overspeed and blow up. Furthermore, such piston pumps are expensive and require small clearances to achieve the necessary seal between the piston and the bore within which it oscillates. Finally, the torque required to drive such piston pumps can be substantial and can require appropriately heavy duty gears and/or drive trains.
Another known type of fuel injection system is the high pressure common rail system wherein a high pressure pump supplies a substantially constant high pressure to a manifold and to timing control nozzles. Such systems may require complicated electronics and solenoid activated devices to achieve proper timing of the opening and closing of the nozzle. Also, such nozzles are either on or off and permit very limited control of the flow rate.